title: Role of glutamate receptors and nitric oxide on the effects of glufosinate ammonium, an organophosphate pesticide, on in vivo dopamine release in rat striatum.
abstract: The purpose of the present work was to assess the possible role of glutamatergic receptors and nitric oxide (NO) production on effects of glufosinate ammonium (GLA), an organophosphate pesticide structurally related to glutamate, on in vivo striatal dopamine release in awake and freely moving rats. For this, we used antagonists of NMDA (MK-801 and AP5) or AMPA/kainate (CNQX) receptors, or nitric oxide synthase (NOS) inhibitors (l-NAME and 7-NI), to study the effects of GLA on release of dopamine from rat striatum. So, intrastriatal infusion of 10mM GLA significantly increased dopamine levels (1035±140%, compared with basal levels) and administration of GLA to MK-801 (250μM) or AP5 (650μM) pretreated animals, produced increases in dopamine overflow that were ∼40% and ∼90% smaller than those observed in animals not pretreated with MK-801 or AP5. Administration of GLA to CNQX (500μM) pretreated animals produced an effect that was not significantly different from the one produced in animals not pretreated with CNQX. On the other hand, administration of GLA to l-NAME (100μM) or 7-NI (100μM) pretreated animals, produced increases in dopamine overflow that were ∼80% and ∼75% smaller than those observed in animals not pretreated with these inhibitors. In summary, GLA appears to act, at least in part, through an overstimulation of NMDA (and not AMPA/kainate) receptors with possible NO production to induce in vivo dopamine release. Administration of NMDA receptor antagonists and NOS inhibitors partially blocks the release of dopamine from rat striatum.
authors.affiliation: Department of Functional Biology and Health Sciences, Faculty of Biology, Campus As Lagoas-Marcosende, University of Vigo, Vigo (Pontevedra) 36310, Spain. lilianfaro@uvigo.es
authors.forename: Lilian R F
authors.initials: LR
authors.lastname: Faro
authors.forename: Brenda V
authors.initials: BV
authors.lastname: Ferreira Nunes
authors.forename: Miguel
authors.initials: M
authors.lastname: Alfonso
authors.forename: Vania M
authors.initials: VM
authors.lastname: Ferreira
authors.forename: Rafael
authors.initials: R
authors.lastname: Durán
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000613:Aminobutyrates / Q000633:toxicity*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D006540:Herbicides / Q000633:toxicity*; D006719:Homovanillic Acid / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009943:Organophosphorus Compounds / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000613:Aminobutyrates; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D006540:Herbicides; D007191:Indazoles; D009943:Organophosphorus Compounds; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D015102:3,4-Dihydroxyphenylacetic Acid; D009569:Nitric Oxide; C003121:phosphinothricin; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole; D019331:NG-Nitroarginine Methyl Ester; D004298:Dopamine; D006719:Homovanillic Acid
keywords: Brain microdialysis; Glufosinate ammonium; HPLC-EC; In vivo dopamine release; NMDA receptors; NOS inhibitors; Rat striatum